In general, a glovebox is a sealed container that is designed to allow a user to manipulate objects within the container when a separate atmosphere is desired. These objects may be (or be associated with) hazardous chemicals, biological agents, or radioactive nuclear materials, for example. Sealed gloves or the like are built into one or more sides of the glovebox and arranged in such a manner that the user outside of the glovebox can place his or her hands into the sealed gloves and perform tasks inside the glovebox without breaking containment. Part or all of the glovebox is usually transparent to allow the user to see the objects being manipulated. Two basic types of gloveboxes exist: (1) those that allow the user to work with hazardous substances, such as hazardous chemicals, biological agents, or radioactive nuclear materials, and (2) those that allow the user to manipulate substances that must be contained within a high purity inert atmosphere, such as argon or nitrogen. It is also possible to use a glovebox for the manipulation of objects in a vacuum. In some cases, the protective shielding of the glovebox sides may be of primary importance.
The gas in a glovebox is typically pumped through a series of treatment devices that remove solvents, water, and oxygen from the gas. For example, heated copper metal (or some other finely divided metal) is often used to remove oxygen, and this oxygen removing column may be regenerated by passing a hydrogen/nitrogen mixture through it while it is heated. The water formed is passed out of the box with the excess hydrogen and nitrogen. It is common to use molecular sieves to remove water by adsorbing it in the pores of the molecular sieves. Such a glovebox is often used by organometallic chemists to transfer dry solids from one container to another, for example. An alternative to using a glovebox for air sensitive work is to employ Schlenk methods using a Schlenk line. One disadvantage of a glovebox is that organic solvents can attack the plastic seals. As a result, the glovebox may start to leak and oxygen and water can then enter the glovebox. Another disadvantage of a glovebox is that oxygen and water can diffuse through the plastic gloves. Thus, inert atmosphere gloveboxes are typically kept at a higher pressure than the surrounding air, so that any microscopic leaks are mostly leaking inert gas out of the glovebox instead of letting air in, if the type of containment allows.
Gloveboxes used for hazardous materials are generally maintained at a lower pressure than the surrounding atmosphere, so that microscopic leaks result in air intake, rather than hazard outflow. Gloveboxes used for hazardous materials generally incorporate HEPA filters or the like into the exhausts, to keep hazards contained. Gloveboxes are often used in the biological sciences, when dealing with anaerobes or high biosafety level pathogens. In applications where radiation exposure is a concern, the gloves and other components may be lead lined. Other materials used in the gloveboxes can include acrylic viewing windows and Benelex shielding composed of wood fiber and plastic that shield against neutron radiation, for example. Manipulation of the lead-lined gloves is onerous work. Some gloveboxes for radioactive work are used under inert conditions, for instance, in nitrogen-filled boxes or argon-filled boxes. The argon boxes may be fitted with a gas treatment system to keep the gas very pure to enable electrochemical experiments in molten salts, for example.
Regardless of the type of glovebox, the safe ergonomic reach of a user that takes into account the weight of an object is a significant issue. It is important that objects within a glovebox are disposed at appropriate distances such that they can be grasped, manipulated, and moved by a user without being dropped and/or resulting in user injury. Thus, what is still needed in the art is a tool that assists the user (or others) in determining where objects should be placed within a glovebox for safe handling by the user. In effect, this tool would translate existing safety guidelines and procedures related to object placement into a simple and easy to use and understand guide tool.